net: use IS_ENABLED(CONFIG_IPV6)

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d56c07a..db03083 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6841,7 +6841,7 @@
 	.sockets_allocated = &sctp_sockets_allocated,
 };
 
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 
 struct proto sctpv6_prot = {
 	.name		= "SCTPv6",
@@ -6872,4 +6872,4 @@
 	.memory_allocated = &sctp_memory_allocated,
 	.sockets_allocated = &sctp_sockets_allocated,
 };
-#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
+#endif /* IS_ENABLED(CONFIG_IPV6) */